Holds a Master’s degree in Engineering and is keen on her own home’s climate. Sometimes we think that Carolina owns every single product she writes about – that’s how profound and insightful her reviews always are.
For 8 years, Richard had been working as an HVAC specialist and AC unit installer since his student years. Now, he’s our main consultant on every technical aspect that may arise during our tests and research.
Last updated: August 01, 2021
If you have asthma, you might already know how important it is to have a good air purifier. Because they pull so many pollutants and contaminants from the air, a lot of the things that can trigger asthma flares are removed, helping you breathe easy. There are a lot of different products out there to choose from so we’re here to help you find the best air purifier for you.
To put together this review, we researched 38 different products, narrowing it down to these top picks. Our Editor’s Choice is the Alen BreatheSmart FIT50, a stylish, effective air purifier that uses four-stage filtration to trap 99% of air particles. It’s backed by a lifetime warranty and is available in multiple colors so you can find the perfect match for your home. If that doesn’t sound like what you’re looking for, we included four other options that we think are pretty awesome, too.
When choosing which products to include in our review, we looked at a few key features, including how many square feet each covers, the fan speed, number of features, and product dimensions. We also considered whether or not it’s covered by a guarantee. The first thing you’ll find is a table where you can see all of our picks side by side. Next are our in-depth reviews of each product followed by a detailed buying guide to help you figure out which is the best product for you.
More features: ionizer function, 48.7 dB noise level in turbo mode, 14-panel colors, timer settings, automatic mode, ozone-safe ionizer
The Alen BreatheSmart FIT50 is our Editor’s Choice. It cleans 900 square feet in only 30 minutes and uses a high-quality HEPA-Pure filter that traps 99% of particles as small as 0.3 microns. A laser sensor detects particles in the air and an indicator light displays the air quality in real-time.
One of the things we really love about this product is the auto-mode. This machine adjusts the fan speed in response to air quality which saves on wear and tear, conserving energy and extending the life of the machine. There are three timer settings, too, plus it’s EnergyStar certified and backed by a lifetime warranty.
WhisperMax technology keeps this machine from interrupting your sleep and can actually help you sleep better by drowning out background noise. It’s available in eight different colors, including stainless, maple, oak, and rosewood so you can choose a design that matches your decor, no matter where you use it.
Reviewers were very happy with this product’s performance and appearance. There were a handful of complaints about the size – at about 23” H x 16” W x 10” D, it is a pretty sizable machine – but the footprint is pretty small so it won’t take up too much space. Users also felt the price was a bit high.
More features: filter replacement indicator, 53 dB noise level at turbo mode, CADR rating 230, dust sensor, night mode
The Oransi Max air purifier is a good choice if you want to clean the air and eliminate odors at the same time. It uses three-stage filtration that includes a pre-filter to get rid of large particles, HEPA filter for small ones, and a carbon filter to eliminate odors. The pre-filter should be cleaned every two months or so while the other filters last about a year. Accessing and changing the filters is easy and tool-free and a filter replacement indicator alerts you when it’s time.
An air quality monitor adjusts the fan speed automatically depending on air quality. This not only ensures that you’re always breathing the best quality air but also protects against overuse since the fan only runs when it has to. It operates quietly, too, so it won’t disrupt your sleep or interfere when you’re watching TV or having a conversation.
For the most part, users are very happy with this product. In fact, most complaints have nothing to do with their performance. Some people felt that both the machine itself and the necessary replacement filters were a bit expensive. There were also a few people who mentioned that it was a little loud when running on high.
Why is it special?
Easy to use
Cleans up to 600 square feet
3-stage filtration includes pre-filter, HEPA filter, and carbon filter
More features: UL Listed, PlasmaTrue™ Technology, 4-stage filtration
We’re calling the Fellowes AeraMax 300 the best air purifier for allergies. It’s certified by the Asthma and Allergy Foundation of America and has a special high-performance mode for when you need to ramp it up a bit during cold, flu, or allergy season.
One of the things we like the most about this product is it uses four-stage filtration. First, there’s a carbon filter to capture large particles and trap odors. Next is the true HEPA filter that removes pollen, allergens, viruses, and mold spores. The third stage is the AreaSafe antimicrobial treatment which prevents bacteria, mildew, and fungus growth on the HEPA filter. Finally, it uses PlasmaTRUE technology which creates an ionized field to remove pollutants from the air.
Another great feature is the Aerasmart sensor. It continuously monitors air quality and automatically adjusts the fan speed to not only maintain clean air but also to save on energy and wear and tear.
There weren’t a lot of complaints about this machine, though some people mentioned that the lights on the display screen were a little too bright. Replacement filters can also be quite costly and are a little hard to find.
For the most part, users agreed that this machine was pretty quiet, though a few people did mention that it seemed a little too loud when running on high settings.
What makes it stand out?
Certified by the Asthma and Allergy Foundation of America
Automatically adjusts the fan speed
Which disadvantages must you keep in mind?
Lights on display are very bright
Replacement filters are hard to find and can be expensive
Can be loud on high settings
Hathaspace Smart True HEPA Air Purifier – Best for Large Rooms
More features: 5-stage filtration, ionizer, 43 dB noise level at turbo mode
The Hathaspace Smart True HEPA Air Purifier is designed for small rooms up to 350 square feet. It’s effective against a range of air pollutants, including allergens, bacteria, smoke, mold, dust, and volatile organic compounds, as well as it is one of the best models among air purifiers for odors.
A quality sensor measures the air and adjusts the fan speed as needed in real-time. It displays the air quality level as green, yellow, or red so it’s easy for you to see how well the machine is working. If you want to adjust the settings yourself, it’s easy to do using the included remote control. You can change them from across the room, including putting the air purifier into sleep mode for whisper-quiet operation at night.
This purifier uses five stages of filtration, the most of any of the products we chose. They include a nano-cold catalyst filter for large particles, a carbon-fiber filter to capture odors, an antibacterial filter that targets smaller particles like bacteria and viruses, a HEPA filter for allergens and dust, and an ionizer to neutralize odors, smoke, and dust.
Some users commented that the machine shakes a little when on the highest setting and, while sleep mode is quieter, the lights on the front of the unit are pretty bright. Replacement filters can be a bit pricey, too.
More features: air quality indicator, eco mode, filter replacement indicator, timer, 53.8 dB noise level at high speed
Finally, we have our budget pick, the Coway AP-1512HH Mighty Air Purifier. This is a great choice for small rooms up to about 361 square feet and the sleek, modern design looks great just about anywhere.
This machine uses four-stage filtration to remove 99.97% of particles from the air. A pre-filter collects large particles and there’s a deodorization filter for odors, a HEPA filter for 0.3-micron particles, and a vital ion generator that reduces the number of particles in the air. A bright LED display lets you know how clean your air is and there’s an indicator so you know when it’s time to change the filters.
The Mighty pollution sensor determines the indoor air quality and adjusts filtration accordingly. You can adjust the settings manually, too. There are three different fan speeds to choose from as well as a one, four, or eight-hour timer. If no pollution is detected for 30 minutes, the machine automatically turns off and goes into eco-mode to conserve energy and prevent unnecessary wear and tear on the machine.
This machine is generally quiet but can be pretty loud on the highest settings. Several people commented that they were very happy with the way this machine performed but wished that it had a remote control or WiFi connection. For a simple budget option, though, it gets the job done.
What stands out?
Great for small rooms
Sleek, modern design
Filter change indicator
3 fan speeds
What cons did we manage to find?
Can be loud on high settings
Only covers 361 sq ft
Things to Consider
Choosing the right air purifier is a great way to clean the air in your home and lower the chances of having an asthma attack. Here’s what you need to know to choose the right one for you.
How air purifiers help easing asthma
Asthma is a chronic condition that results in inflammation of the airways. They narrow making it difficult for oxygen to get into the lungs. People with asthma take medication for long term management and for emergency treatment but the best way to minimize asthma symptoms and avoid an asthma flare is to eliminate triggers. And the best way to do that is to use an air purifier.
Air purifiers – particularly those with HEPA filters – are effective at removing some of the most common asthma triggers from the air, including smoke, dust, pet dander, and mold, but even filter-less models such as, for example, Dyson air purifiers can help you. If you have asthma, an air purifier is an ideal way to make sure you can breathe easy when in your own home.
The products we chose for our list range in price from around $140 to $530. While it’s important to pick something that fits into your budget, it’s also a good idea to choose the best air purifier you can comfortably afford. Since asthma is a chronic condition, it’s something you’ll be coping with for your entire life. The right air purifier could last year after year.
Features to consider while buying the perfect air purifier for asthma
Here are some of the specific features to think about when choosing the right air purifier for you.
Consider the size
These products range in size a bit but, generally, they might be a little larger than you’d think. For the most part, the products we chose are rectangular in shape, taller than they are wide. That said, they’re pretty narrow in comparison so they don’t have an exceptionally large footprint.
It’s important that you leave enough room around the machine so the vents are able to pull air in and push it out without anything getting in the way.
The coverage area
Coverage area refers to the number of square feet an air purifier is able to cycle. The Alen BreatheSmart FIT50 covers up to 900 square feet while the Hathaspace Smart True HEPA Air Purifier works in a space about 350 square feet.
It’s important to make sure you choose the right size for your room. If you use an air purifier that isn’t powerful enough, it won’t be effective.
Air purifiers use a number of different filters. Some, like ionic air purifiers, actually don’t need any, some only use two while others use as many as three or four.
All of these products have a HEPA filter, an absolutely essential part of an air purifier. HEPA filters are designed to trap the smallest airborne particles, as small as 0.3 microns in size. They’re around 99% effective so they remove just about every speck of allergens, bacteria, mold, and viruses from the air which is exactly what you need if you have asthma.
Most of these products also have some sort of pre-filter which is designed to trap larger particles before they get to the HEPA filter. These filters trap the things you can see like the large pieces of dust or dander you may see floating around in the air.
If you’re worried about odor, look for an air purifier with a carbon filter. Carbon is great at trapping smells and impurities.
Fan speed adjustment
Most of the items on our like, like the Oransi Max, have a feature that automatically detects the amount of pollution in the air and automatically adjusts the speed of the fan as needed. Most allow manual adjustments, too, and have around three fan speeds.
Clean air delivery rate, or CADR, is determined by the volume of airflow and efficiency of the filters. The scale goes up to 450 depending on the type of particle that’s being measured. The higher the CADR, the cleaner is the air an air purifier is able to put out. One thing to note, though, it that CADR ratings are based on the highest setting on the air purifier. If you usually use lower settings, it’s important to know that the air purifier isn’t performing as well as it can.
Some of these products have color-coded displays that tell you how well the air purifier is working. For example, it might have a red light when the air quality is poor that changes to green as the purifier cycles the air. This is an easy way to make sure the air purifier is really getting the job done.
Guarantees on these products vary a bit. Our Editor’s Choice is backed by a lifetime warranty while the Fellowes AeraMax 300 is covered for three years. Guarantees and warranties always matter, particularly in a product like this. Whatever air purifier you choose should last as long as possible. It’s easier to have faith in the longevity and performance of a product that has a strong warranty.
Noise is relative – what some people find unbearable doesn’t bother other people at all. That said, most of these products are pretty quiet on the lowest settings but can get pretty loud when on the maximum settings. The good news is that a lot of them mimic white or pink noise so if you like that kind of sound while you’re sleeping, the loud noise might not bother you too much.
As we mentioned, some of these products have sensors that determine how much pollution is in the air and adjust the fan speed accordingly. This is a great feature for two reasons. One, it saves energy. And, two, it prevents unnecessary wear and tear, extending the life of the machine.
Tips for asthma treating
One of the most important things when choosing an air purifier for asthma is the HEPA filter. Other machines will clean some of the dust and allergens from the air but the only way to make sure you get as much as possible is to use a HEPA filter.
Place the air purifier somewhere where the intake and outflow vents are open to the room. You want it to circulate as much air as possible so hiding it behind a couch or placing it by a doorway isn’t as effective.
It’s also important to note that, while an air purifier can help symptoms and reduce the chances of a severe asthma attack, they’re not a replacement for regular medication or a rescue inhaler.
Ozone air purifiers can make asthma worse which is why we didn’t include any in our product review. The gas that they produce can actually irritate the lungs and they don’t remove asthma triggers from the air.
It’s difficult to say because they do different things. Air purifiers remove microscopic triggers from the air, which undoubtedly helps keep asthma under control. A humidifier doesn’t remove anything from the air but does prevent it from being too dry which in and of itself can trigger an asthma flare.
Air purifiers all work a little differently, depending on the model, but generally, it goes like this. The machine pulls in air from the room, sending it through the filters. The filters go from largest to smallest, that is the air travels through the filters that remove large particles first before passing through the carbon filter or a HEPA filter. Then, the air is expelled from the machine so it can recirculate through the room.
Our Editor’s Choice is the Alen BreatheSmart FIT50 air purifier. It has the largest working area of all the items in our review and the four-stage filtration is effective at trapping 99% of particles in the air. Auto-mode adjusts fan speed as needed and it’s backed by a lifetime warranty.
The Oransi Max uses three-stage filtration and removes particles and odors from the air. This product automatically adjusts to the indoor air quality so it only runs when it has to and it’s quiet enough that it won’t disrupt your sleep or when you’re watching TV.
Finally, we recommend the Fellowes AeraMax 300 as the best air purifier for asthma and allergies. It’s certified by the Asthma and Allergy Foundation of America and has a high-performance mode for cold, flu, and allergy season. A sensor continuously monitors air quality and adjusts as needed for maximum effectiveness while avoiding excess wear and tear.